C. M. Korsgaard is a Kantian philosopher, she proceeds in her works with the guidance of Kant, and by this guidance, she argues important subjects as "agent and identity", "self", "normativity", "practical reason", and "animals". In her works she especially argues that normativity has a necessary relationship with human nature, it has a psychological power in human nature as a form of necessity, it functions as the creator of the human soul. Korsgaard believes that: Only the rational person reaches to "the normative principles, laws which will govern the things she/he does and believes", he/she has the skill "to normatively manage himself/herself". This skill is not available in other non-human animals; they all do not have a capacity of reason, rationality rather they only act with their evolutionary instincts, their natural structures. Korsgaard, however, says that we must not exaggerate this difference and that this difference does not make us morally superior to them. For animals, like us, value their lives, pursuit certain goods and ends, live with certain functions (ergon). In this paper, we will see the Kantian theory which Korsgaard argues about animals.